Multiprocess Firefox

In current versions of desktop Firefox, the entire browser runs in a single operating system process. In particular, the JavaScript that runs the browser UI (also known as "chrome code") runs in the same process as the code in web pages (also known as "content" or "web content").

Future versions of Firefox will run the browser UI in a separate process from web content. In the first iteration of this architecture all browser tabs will run in the same process, and the browser UI will run in a different process. In future iterations, we expect to have more than one content process. The project that's delivering multiprocess Firefox is called Electrolysis, sometimes abbreviated to e10s.

Normal web pages are unaffected by multiprocess Firefox. People working on Firefox itself and Firefox add-on developers will be affected if their code relies on being able to access web content directly.